Sometmes balance point may not be obtained on the potentiometer wire. Why?

A cell of e.m.f. 4 V and of negligible internal resistance is connected in series with a potentiometer wire of length 400 cm. The e.m.f. of a Leelanche cell is found to be balacned at 150 cm from the positive end of the potentiometer wire. What is the e.m.f. of the Leclanche cell ?

A potentiometer wire of length 100 cm has a resistance of 10Omega. It is connected in series with a resistance and an accumulator of emf 2V and negligible internal resistance. A source of emf 10 mV is balanced against a length of 40 cm of the potentiometer wire. what is the value of the external resistance?

Figure 3.35 shows a 2.0 V potentiometer used for the determination of internal resistance of a 1.5 V cell. The balance point of the cell in open circuit is 76.3 cm. When a resistor of 9.5 Omega is used in the external circuit of the cell, the balance point shifts to 64.8 cm length of the potentiometer wire. Determine the internal resistance of the cell. :

A potentiometer is connected between A and B and the balance point is obtained at 203.6cm. When the end of the potentiometer connected to B is shifted to C, then the balance point is obtained at 24.6cm. If now the potentiometer be connected between B and C, the balance point will

There is a potentiometer wire of length 1200 cm and 60 mA current is flowing in it. A battery of emf 5V and internal resistance of 20 ohm is balanced on potentiometer wire with balancing length 1000 cm. find the resistance of the potentiometer wire